This section provides background information related to the present disclosure, which is not necessarily prior art.
FIG. 1 illustrates a prior art heating, ventilation, and air conditioning (HVAC) assembly at reference numeral 10A. The HVAC assembly 10A is generally configured for use with a vehicle HVAC system. The HVAC assembly 10A includes a case or housing 12, which defines a center or rear zone 20, a first outboard or driver's side zone 22, and a second outboard or passenger's side zone 24. The rear zone 20 is configured to direct airflow to a rear of the vehicle that the HVAC assembly 10A is installed in. The driver's side zone 22 is configured to direct airflow to a front, driver's side of the vehicle. The passenger's side zone 24 is configured to direct airflow to a front, passenger's side of the vehicle. Although the first outboard zone 22 is described as a front, driver's side airflow zone, and the second outboard zone 24 is described as a front, passenger's side airflow zone, one skilled in the art will appreciate that the zones can be reversed such that the first outboard zone 22 is a front, passenger's side airflow zone, and the second outboard zone is a front, driver's side airflow zone.
Arranged at the rear zone 20 is a rear zone airflow door 30, which is movable to control airflow through the rear zone 20. Arranged at the driver's side zone 22 is a first outboard airflow door, or driver's side airflow door 32. The driver's side airflow door 32 is movable to control airflow through the driver's side zone 22. Arranged at the passenger's side zone 24 is a second outboard airflow door, or passenger's side airflow door 34. The passenger's side airflow door 34 is movable to control airflow through the passenger's side zone 24.
Mounted within the case 12 is a first shaft 40, and a second shaft 42. In the example illustrated, the first shaft 40 extends through the second shaft 42. The first shaft 40 extends across the driver's side zone 22 to the rear zone 20, where the first shaft 40 is in cooperation with the rear zone airflow door 30. The first shaft 40 may extend to the passenger's side zone 24, or may terminate prior to reaching the passenger's side zone 24. Rotation of the first shaft 40 by a first servo 50 results in movement of the rear zone airflow door 30 to control airflow through the rear zone 20. The first shaft 40 rotates independent of the second shaft 42. The second shaft 42 is indirectly rotated by a second servo 52. Specifically, the second servo 52 rotates a first gear 60, which rotates a second gear 62. The second gear 62 is coupled to the second shaft 42. The second shaft 42 is in cooperation with the driver's side airflow door 32 such that rotation of the second shaft 42 moves the driver's side airflow door 32 to control airflow through the driver's side zone 22. The case 12 further includes a third shaft 44 arranged at the second outboard zone 24. The third shaft 44 is in cooperation with the passenger's side airflow door 34, such that rotation of the third shaft 44 by any suitable third servo (not shown) moves the passenger side airflow door 34 to control airflow through the passenger's side zone 24. The third shaft 44 rotates independent of each one of the first shaft 40 and the second shaft 42.
The HVAC assembly 10A of FIG. 1 is configured as a tri-zone assembly because each one of the rear zone airflow door 30, the driver's side airflow door 32, and the passenger's side airflow door 34 is independently movable in order to independently control airflow through each one of the rear zone 20, the driver's side zone 22, and the passenger's side zone 24. In some applications it is desirable to convert the HVAC assembly 10A of FIG. 1 from a tri-zone assembly to a dual-zone assembly, such as is illustrated in prior art FIG. 2 at reference numeral 10B.
Prior art FIG. 2 illustrates an HVAC assembly 10B, which is similar to the assembly 10A, but converted to a dual-zone assembly by replacing the first shaft 40 and the second shaft 42 with a fourth shaft 46 and a fifth shaft 48. The fourth shaft 46 is coupled to the fifth shaft 48. The fifth shaft 48 is coupled to the second gear 62. Thus rotation of the first gear 60 by the second servo 52 rotates the second gear 62, and rotation of the second gear 62 rotates both the fourth shaft 46 and the fifth shaft 48 together. The fourth shaft 46 is in cooperation with the rear zone airflow door 30, and the fifth shaft 48 is in cooperation with the driver's side airflow door 32. Because the fourth shaft 46 and the fifth shaft 48 are coupled together and rotate together, the airflow doors 30 and 32 will also move together. As a result, the airflow doors 30 and 32 cannot be controlled independent of one another, and thus airflow through the rear zone 20 and the driver's side zone 22 cannot be independently controlled, as is the case with a dual zone assembly. The third shaft 44 is not coupled to either the fourth shaft 46 or the fifth shaft 48 (although the third shaft 44 may abut the fourth shaft 46 as illustrated), and thus the third shaft 44 remains independently rotatable. As a result, the passenger's side airflow door 34 also remains independently movable to independently control airflow through the passenger's side zone 24.
While the dual zone HVAC assembly 10B of FIG. 2 is suitable for its intended use, it is subject to improvement. For example, the connection between the fourth shaft 46 and the fifth shaft 48 occurs within the case 12, thereby making the HVAC assembly 10B difficult to assemble, and making it difficult to visually confirm that the fourth and fifth shafts 46 and 48 have been properly connected together. An improved dual-zone HVAC assembly would therefore be desirable. Specifically, an improved dual-zone HVAC assembly made from a converted tri-zone HVAC assembly, such as the HVAC assembly 10A of FIG. 1, would be desirable. The present teachings advantageously provide for such an improved dual-zone HVAC assembly having the advantages set forth herein, as well as numerous others as one skilled in the art will appreciate.